Self-adhering spacer blocks or panels are useful for a number of purposes. The spacer blocks are provided with a pressure-sensitive adhesive coating on at least one face, and are positioned about a product to prevent damage to the product while it is moved within the factory to various manufacturing steps, and to prevent damage when the product is shipped out of the factory.
Conventional self-adhering spacer blocks are formed of a generally planar, rigid material such as Styrofoam. Other spacer blocks are formed of honeycomb materials which are extremely strong and have a very high strength-to-weight ratio compared to other materials on the market.
The term "honeycomb" is derived from the mass of hexagonal cells of wax built by honey bees and the term is used to refer to a pattern resembling that of a honeycomb. The honeycomb material is made from a relatively high density kraft paper, but can also be made of recycled paper, plastic, or other suitable materials. The material is arranged in a generally hexagonal pattern that resembles a honeycomb, and also has a generally flat top facing layer and bottom facing layer. The honeycomb material in the hexagonal configuration has a high column strength that results in the loads being carried by the honeycomb material being distributed over a series of braced columns. The honeycomb material is also extremely crush resistant.
Conventional honeycomb panels have a central core with vertically extending columns that define cells with open ends, and a pair of opposing generally planar facing layers of relatively rigid material that overlie and are adhesively secured to the ends of the columns. The rigid facing layers are made from various suitable materials ranging from thin metal sheets, such as aluminum or steel, to lighter materials such as kraft linerboard, heavy plastic, or plywood.
The honeycomb panel can be provided with a pressure-sensitive adhesive coating on at least one face to define a self-adhering spacer block or panel.
One of the problems with spacer blocks having at least one planar and rigid face that is coated with pressure-sensitive adhesive is that they may not present a sufficient area of contact to grip and hold a product that has a curved or irregular surface, such as dimples or corrugations.
The rigidity of conventional spacer blocks is also disadvantageous in that the spacer block will not deform to accommodate curves or irregularities in the configuration of the product that confronts the spacer block. When the spacer block has rigid faces that are unyielding in the direction normal to the plane of the faces, the projecting portions of the product can break when pressed against the strong and rigid spacer block, thereby damaging or destroying the product.
Another problem with spacer blocks having rigid faces is the tendency to scratch or mar the surface of the products that they abut against.
One attempt to overcome these problems is disclosed in commonly assigned United States patent application Ser. No. 201,148, filed Oct. 27, 1980 now abandoned. That application discloses a panel of honeycomb material having a flexible surface that is deformable within the voids that are defined by the honeycomb cell walls to accommodate irregularities in the product configuration. Thus, a portion of the object becomes positioned between the planes of the opposing facing layers of the honeycomb panel. The foregoing arrangement has a column strength that is somewhat reduced as compared to a panel having opposing facing layers that are both formed of a rigid material.